message_send: Add service_queue_events to SendMessageRequest.

We should not monkey-patch message when unnecessary. Adding
`service_queue_events` to `SendMessageRequests` suits our need to type
safety here.

Signed-off-by: Zixuan James Li <p359101898@gmail.com>

zerver/actions/message_send.py

@@ -818,7 +818,7 @@ def do_send_messages(
 
             ums.extend(user_messages)
 
-            send_request.message.service_queue_events = get_service_bot_events(
+            send_request.service_queue_events = get_service_bot_events(
                 sender=send_request.message.sender,
                 service_bot_tuples=send_request.service_bot_tuples,
                 mentioned_user_ids=mentioned_user_ids,
@@ -983,7 +983,8 @@ def do_send_messages(
 
                 send_welcome_bot_response(send_request)
 
-        for queue_name, events in send_request.message.service_queue_events.items():
+        assert send_request.service_queue_events is not None
+        for queue_name, events in send_request.service_queue_events.items():
             for event in events:
                 queue_json_publish(
                     queue_name,

zerver/lib/message.py

@@ -171,6 +171,7 @@ class SendMessageRequest:
     deliver_at: Optional[datetime.datetime] = None
     delivery_type: Optional[str] = None
     limit_unread_user_ids: Optional[Set[int]] = None
+    service_queue_events: Optional[Dict[str, List[Dict[str, Any]]]] = None
 
 
 # We won't try to fetch more unread message IDs from the database than